水泥土流变特性的试验研究

Experimental Study on the Rheological Properties of Cement Soil

利用土体流变试验机对温州地区水泥土进行了流变试验,研究结果显示:水泥土具有较强的流变性,水泥土的流变特性随轴向应力水平的增大而加剧;同一围压下,轴向应力水平越大,应变速率也越大;水泥土的瞬时变形非常显著;随着围压的增大,流变变形有减小的趋势,围压对水泥土的流变变形起限制作用。水泥土的流变特性可以采用经验模型和三维Burgers模型进行描述。对水泥土的电镜照片进行分析,发现水泥土内部存在着许多裂纹、孔隙等初始损伤。随着应力水平提高,水泥土体内部出现新的损伤;应力水平越大,持续时间越长,损伤积累越多,因此水泥土流变特性随应力和时间增加而加剧,稳态速率增加。

Rheological test of cement soil in Wenzhou area was carried out by using soil rheological test machine.The results showed that cement soil had a strong rheological property,and it increased with the increases of the axial stress level. Under the same confining pressure,the greater the axial stress level,the greater the strain rate;Instantaneous deformation of cement soil was very significant. With the increases of the confining pressure,creep deformation tends to decrease,thus the rheological deformation of cemented soil would be limited by confining pressure. The rheological characteristics of cement soil can be described with empirical model and three-dimensional Burgers model. Based on the analysis of SEM photographs of cement soil,there are many cracks and pores in the cement soil. With the increase of stress level,the new damage occurred in the cement soil body. The greater the stress level,the longer the duration,the more damage accumulation. Rheological properties of cement soil increased with stress and time,and also the steady-state rate increased.